Magnetically operated device



A. G. STIMSCN IAGNETICALLY OPERATED DEVICE Filed Dec. l, 1938 March 4,1941.

Fig. z

Inventor". Allen G. Sti son, 12j )Q/ Hi tborng.

'Ptentedlz Mar. 4, 1 941 UNITED sum-"riss:

PATENT OFFICE 2,233,925 mons'ncsur ori-maren DEVICE .uien G. simsen.smmwudy, N. Y., mmm to' Generalllectric Company, a corporation of NewYork applicati@ December 1, 193s, serial No. 243.376 s claims. (ci.17a-33e) at the point o! required magnetic force. The

eil'ectotthisshadingcoilistodisplacethemagnetic ilux threading itrelative to the ilux not .threading it, though. pursuing a parallelpath. 5 "lhis displaced or shaded nur lags the unshaded nur by anelectrical angle of less than 90 electrical degrees. Since thedirections oi these two components of ilux are parallel. each providesits own component of magnetic force across the 0 pole face varyingsinusoidally though slightly distorted by saturation oi.' the iron poleface. Each ci.' these force components is of zero value twich eachcycle, but so long as the shaded component lags the unshaded component.the sum 5 oi these two forces is never zero. One feature of my inventionrelates to the provision of an improved pole shader construction using apair of short-circuited windings, the iirst oi which enciicles a portionof the magnetic core and the o second of which encircl a second portionof the magnetic core as well as encircling the nrst portion oi' themagnetic core and leaving a third portion of the core unshaded. In thismanner a threephase ux is provided at the pole face ot s the core memberwhich gives a more uniform pull on the armature and therefore, morequiet operation and greater total pull.

Another feature oi my invention relates to a -reslllently mountedmovable 1contact carriage g operable between an upper and lower xedoontact by the armature of the relay and adapted to provide a wipingengagement of the movable contacts with either of the nxed contacts.

For a more complete understanding of all the 3 features of my invention,reference should be had to the accompanying drawing in which Fig. l is aplan View of a magnetically operated relay embodying my invention; Fig.2 is a left side elevational view of Fig. l; Fig. 3 is a sectional 3view taken along the line 3-3 of Fig. l looking in the direction ofthearrows; Fig. 4 is an inverted sectional view taken along the line 4-4of Fig. 1 looking in the direction oi the arrows; Fig. 5 is an invertedsectional view taken along s the line 5 5 oi Fig. l looking in thedirection of the arrows; Fig. 8 isan exploded view ot some o! the partso1 the relay shown in perspective.

Referring to the drawing, I have shown my invention in onejorm asapplied to a magnetical- -ly operated relay.- The relay includes a base:s

0i.' suitable insulating material upon which the various parts aremounted and secured. The bottom face of the base lll, best shown as theupper edge o! the inverted sectional view of the relay in Fig. 4, isprovided with a groove I2 ex- 10 tending longitudinally thereof intowhich one'. leg o1 an L-shaped magnetizable frame I3 is =secured bymeans ot the hollow rivets or eyelets ll and Il cooperating with thebase. The hollow rivets il and l5 themselves constitute 15 suitable boltholes in the base I0 into which bolts may be inserted for fastening therelay to 1a panel or the like. 'I'he other leg of the L -shapedmagnetlzable frame il extends upwardly' along one side ot the base IU;as seen in Fig. '3 pr0 20 jectin'g a short distance above the upperportion ol the base. A portion of the base Il is moulded with an openingacross which extends the frame I3 as shown in Fig. 5 whereby a well orrecess is formed into which a core member I8 25 and its energizingwinding are disposed. The core memberv i8 consists essentially oi aseries of laminations of magnetizable material fastened together bymeans of the rivets Ita to form an elongated pole piece or core memberof substan- 80 tially rectangular cross-section. The vertically disposedcore member l0, which extendsv upwardly from the bottom of the base ||lin the well provided therefor, is surrounded by a number oi. turns oftine wire constituting an ener- 35 gizlng coil H provided at its sideswith the terminals I8, the core member I8 forming a support for thewinding il and separated therefrom by a sleeve of insulating material i9which surrounds the core member. v 4,()

As shown in Fig. 6, the core I8 has its lower end positioned in a recess2l struck into an auxiliary frame plate 2| which is fastened to the coremember I6 by a screw 22 threaded longitudinally into the bottom o! thecore member. A 45 pair of extensions or ears 23 are provided on theauxiliary frame plate 2| having the holes 24 therein adapted to receivethe screws 25 which are threaded into the frame I3 to secure theauxiliary frame plate 2| thereto. As shown, I 50 have provided a sheetoi insulating material 2G, such as paper, between the auxiliary frameplate 2| and the main frame I3 to increase the reluctance ot themagnetic circuit including these two members. On the auxiliary frameplate 2| 55 opposite the extensions further extension or nib a recess orslot in the Wall thereof for holding in position on the base.

With the auxiliary frame ing means I have 23, I have provided a 21 whichregisters with base I3 and engages a the auxiliary plate 2| plate 2I andfastenprovided, the core member I 6. the energizing winding I1, andl theauxiliary frame plate 2| may be easily assembled and disassembled fromthe base I and main frame I3 as a unitary structure when the relay ismounted on a panel. Thus, one is enaabled to make replacements in theheld, particularly of the energizing winding I1, without disturbing therelay on its mounting. To disassemble the unitary core and winding, itis only necessary to loosen the screws 25 from the frame I3 and give thecore I3 a slight twist or rotary motion to displace the nib 21 on theauxiliary frame plate 3l from its recess in the base I0 and then removethe core unit from its well in the base.

The screws 25, besides being easily accessible from the upper part otthe base I0 for uniastening by means of a screw driver, are alsodisposed in the holes 24 in the auxiliary trame plate 2| in a manner sothat they will not fall out while these parts are being assembled ordisassembled. At their lower ends the screws 25 are provided with athreaded portion 28 and at their upper ends nearest the head of thescrew with an under cut portion 23 of reduced diameter. By providinginternal threads in the holes 24, the lower threaded portions 23 of thescrews 25 must be ilrst threaded through the holes 24. After that,

the under cut portions 23 of the screws 25 are loosely disposed in theholes 2Q`so that the screws 25 may be threaded into screw holes in thetrame I3 to fasten the auxiliary frame plate 2I to the frame. Because ofthe internal threads in the holes 24, the screws 25 are not easilyremovable from the plate 2I without iirst aligning the threads i'orscrew engagement and, therefore, are not likely to fall out of theauxiliary frame plate during assembly or coil replacement.

As hereinbefore explained, to provide a more uniform pull and increasedquiet torque characteristics in the alternating-current magnet. I haveprovided a pole shading construction comprising a pair of parallel slots30 and 3I in the upper end oi' the core member I6 which divide thecross-sectional area of the upper end ,of the core member into threedistinct areas, which taken together comprise a single pole face 32 onthe core. One of the three extending portions of the core member I6comprising the pole face 32 is encircled by a shunted pole shaderwinding 33 which m 7 be formed of two short-circuited turns of copperwire or punched copper plates to provide a low resistance shader. Themiddle extension on the core member is encircled by a larger shuntedpole shader winding 34 which also surrounds the shaded extensionencircled by the pole shader 33 and may comprise a single shortcircuitedturn of copper wire of substantially greater resistance value than thewinding 33. The third extension on the core member I8 having no poleshader thereabout constitutes the unshaded portion of the pole face 32.The pole shaders 33 and 34 are secured in the grooves 30 and 3irespectively by swaging the these grooves. As shown in Fig. 3, it willbe noted that the upper surfaces oi' the pole shaders 33 and 34 are onsubstantially the same plane, the slot 3I being only made deep enoughfor this `wardly extending leg purpose, and no deeper. to avoid undueweakening of the core member I3 at this point.

The cooperating individual shader windings 33 and '34, when properlyproportioned, are well adapted to change the flux characteristics oi.'the core member I to provide a more uniform pull and greater quiettorque thanican be obtained with a single shader winding. The threephase iiux components provided thereby. when acting together, have agreater minimum intensity than the usual two phase flux. The intensityof this minimum value of iiux' isa determinant of .quiet Viiux valueduring each cycle, the less is the likeliing 331s, in eiect, doublyshaded.- A three phase component at the face lwhich i'ollowsenergization current in The middle portion of the pole tace 32 has aiiux component which lags the energization current by an electricalangle oi' less vthan 90, and the ux at the doubly shaded por`- tion lagsthe energization current to a greater extent than the middle portion,but less than 90 electrical degrees. Relative lag is determined brelative amount of shading provided by the shading windings 33 and 34.

Referring now to Fig. 3, the top o! the upof the frame I3 is providedwith a iulcrum edge 33 on which an armature .side oi' the fulcrum edge35 on the frame I3 is a projection 31 cooperating with a shortprojecting portion 38 of the armature 35 which extends across thefulcrum edge 35 and rests thereon. The projecting portion 33 of thearmature 35 is disposed between the projections 31 on the frame whichprevent any substantial lateral displacement of the armature 35 on theIulcrum edge 33. The upper ends of the extensions 31 on the trame I3extend laterally'inwardly over the projecting portion 33 of the armature35 in an overhnging relation thereto for preventing any substantialupward movement oi.' the armature 35 oli .of the fulcrum 36. Theprojecting portion 38 of the armature 35 isnotched at either side toform the shoulders 39 which cooperate with the extensions 31 on theframe I3 to prevent any sub stantial longitudinal movement oi' thearmature 35 on the tulcrum 36 in one direction. Secured to the uppersurface of the armature 35 is a spring strip 4I) extendinglongitudinally thereof having a bent end portion 4I adjacent the tulcrumedge 36 which cooperates with the frame I3 to prevent any substantiallongitudinal movement of the armature 35 on the iulcrum 3 6 in the otherdirection. In other words, the armature 35 is positioned on the fulcrumedge 38 and is prevented from moving more than a very limited amountlongitudinally and laterally thereon by reason of the cooperating spring40, the extensions 31 on the trame. and the shoulders 33 on thearmature. By raising the end 6I, the

each cycleV is lessened. By en.

I spring 40 is deilected upward and removal of the armature 25 from theframe is permitted.

The main body of the amature 35 extends laterally above the oore memberI5 and is pivotally movable about the fulcrum 45 adjacent the pole face32 upon energization of the coil I 'L The opposite end -of the springstrip 40 from that nearest the fulcrum 25 extends beyond the end of thearmature 45 and is resiliently supported by spring means which normallybias the armature to its unattracted position as well as provide aconnection with contact operating means operable by the movement of thearmature between its attracted and unattracted positions. Ihe supportand contact operating means includes a guide member or post 42 which maybe formed by a metal strip staked at its lower end into the frame I3.The upper end of the guide post 42 contains a slot or groove 42 runninglongitudinally thereof into which one prong of a. trifurcated endportion 40a of the spring strip 40 is disposed for movement up and downin .the groove 43. On the metal guide post 42, I have slidably mounted acontact carriage 44 of insulating material, the carriage 44 having acentral aperture for receiving the guide post 42. The contact carriage44 is molded with suitable wellshaped upper and lower ends to receiveand seat a pair of helical springs 45 and 45 therein. The springs 45 and45 encircle the guide post 42, the spring 45 serving to support thecarriage 44 and resting on the insulating liner 25 of the trame i3'. Thespring 45 is interposed between the upper side of the carriage 44 andthe end 40a of the spring 40 to provide a resilient connection tortransmitting the downward movement ot the armature 35 to the carriage.

For adjusting the disposition of the armature 25 with respect to thefree position of the spring 45, I have provided the spacing washers 4'|be tween spring strip 40 and the upper end of the helical spring 45. Thespacing washers 41 are provided with an aperture 45 for receiving theguide post 42 and `have a pair of diametrically opposed inwardlyextending portions 49 projecting into the groove 43 on the guide post42. TheA ends of the projections 49 are spaced apart slightly less thanthe thickness of the end oi' the guide post 42 which forms the top wallof the groove 43. These washers may be made of any resilient material,preferably in the form of thin metal punchings which may be pushed overthe end of the guide post 42 in the number desired and which will beretained in place thereon by the projections 49 disposing themselves inthe groove 43. Because of the projections 4S, the spacing washers areunable to fail oil.' of the guide post 42 but may be easily assembled onand removed from the post, the projections 49 being forced apartslightly for this purpose in the course of assembly or removal.

Secured to the base i are the terminals 50a, ta, 52a, and 53a eachconnected to one of the fixed contacts 50, 5i, 52, and 58. The fixedcontacts 50, 5| and 52, 52 comprise spaced apart pairs of contacts whichcooperate with the movable contacts 54 and 55 respectively disposedtherebetween for engagement with the upper set 5U and 52, as seen inFig. 4, when the armature 35 is in the attracted position, and forengagement with the lower set of contacts 5I and 5I when the armature isin the unattracted position. Extending at opposite sides of the contactcarriage 44 are a pair of arms 55 and 5l on which the movable contactsare mounted, the arms being displaced `oiI the center line of guide post42 or offset for providing a leverage means on said contact carriage 44whereby the carriage is given a tilting or pivotal movement as thecontacts are engaged and disengaged. lThe contact carriage 44 isslidable on the guide post 42, as hereinbefore mentioned, and it is alsoarranged for limited pivotal movement about the guide post 42 so thatthe movable contacts 54 and 55 are given a wiping or rolling action uponengagement and disengagement with the respective fixed contacts.

The effectiveness and uniformity of this wiping action is enhanced byproviding the pairs of pivot points 58 and 59 on the contact carriage 44upon which the springs 45 and 45, respectively, are seated. The centerlines of the pivot points are on the same vertical plane and aredisposed adjacent the narrow edges of the guide post 42. The fixedcontacts are also disposed on a common vertical plane which is parallelto the plane of the pivot points. In this manner, as the carriage 44 isslidably moved up and down along the guide post 42, a definite momentarm is provided for tilting the carriage 44 as the contacts engage anddisengage. This definite moment arm for the tilting oi' the contactcarriage 44 provides a substantially uniform wiping and rollingengagement of the contacts desirable for avoiding and breaking pin pointwelds on the contact surfaces, scrubbing dust and foreign mattertherefrom and providing good engagement of the contacts.

Connecting the movable contacts 54 and 55 in circuit with a pair of'terminals 80 provided therefor secured to the base i0 arethe resilientconductors 5| which are adapted to tlex in accordance with the movementof the contact carriage. 4The conductors 5| are of substantiallyU-shaped configuration having outwardly bent ends at the point ofconnection with the terminals 50 'and movable contacts 54 and 55. Tominimize the life shortening eflects of fatigue to which the conductors8i are subjected during frequent operation of the relay over longperiods by reducing the deiiection and hence the stress at the points ofsupport, I have provided the strengthening members 52 and 53 at theseoutwardly bent end 'portions of the conductors 5i. The strengtheners 52and 53 comprise strips of metal or other flexible material fitted alongthe inner curvature of the bends of the conductors 5i which assist indistributing the bending stress at these points over a wide area andgreatly assist in prolonging the life oi' the conductors 5 l.

In operation of the relay, the armature 25 is normally supported freelyby the springs 45 and 46 in the unattracted position above the pole face32 of the core member I5. The movable contacts 54 and 55 are maintainedin engagement with the upper fixed contacts 5i and 53 for making thecircuit including the terminals 5Ia, the contacts 5| and 54, a.conductor 5| and a terminal 50, and the circuit including the terminal53a, the contacts 53 and 55, a conductor 5|, and a terminal 50. When thewinding i1 is energized, the armature .35 is attracted down'- wardly tothe core i5 and the force of its movement is transmitted to the contactcarriage 44 by the helical spring 46. The downward movement of thecontact carriage 44 dlsengages the previously engaged contacts 5i and 54also 53 and 55. Upon suillcient downward travel, the

l5 and 46 are bearing. This rocking action wipes.

the movable contacts il and Il across the fixed contacts Il. and I2 ina.Y desirable manner and ygood engagement of these contacts is provided.

Two further circuits' are then completed and each includes one o! thelower fixed contacts Il and 52 instead of the upper nxed contacts SI and53 as before. The wiping engagement of the contacts 5i and 54 also iland Il occurs in an identical manner when the armature Il moves backtoits unattracted position. Moreoven in 4each instance as the contactsdisengage, some wiping action is effected between those contacts.

The switch device described herein is covered in my divisionalapplication, Serial No. 331,662, med April 25, i940. Y

While I have shown a particular embodiment o1 my invention, it will beimderstood. o! course. that I do not wish `to be limite'dthereto sincemany modiiicationsv may be made. and I therefore contemplate by theappended claims to cover any such modiilcations as fallwithin 'the truespirit and scope of my invention. l

What I claim as new and desire to Letters Patent of the United Statesis:

1. A magnetically operable device comprisin'ga 'nase of insulatingmaterial adapted to be mounted on a-panel, a magne'tic frame mounted onthe bottom oi said base, a core member, an energizing winding on saidcore member,an auxiliary frame plate secured to the bottom of said coremember having an extension thereon projecting beyond the periphery ofsaid energizing winding; fastening means including said extension ofsaid auxiliary frame plate accessible from the upper securel .side ofsaid base for securing said auxiliary frame plate to said frame therebyenabling easy removal of said auxiliary trame plate.' core member. andenergizing winding from said frame and base when said device is mountedon a panel.

2. A magnetically operable device comprising a base of insulatingmaterial adapted to be mounted on a panel, a magnetic frame mounted onthe bottom of said base, a core member and an energizing windingtherefor projecting upwardly in a well provided in said base, an aux'iliary frame plate secured to the bottom of said c-:are'member having adepression struck therein in which the end of said core member is seatedand fastened, fastening means for securing said core member in said wellon said base comprising a projection on said auxiliary frame plate whichcooperates with a recess insaid base and may be positioned in anengaging relationship with a wall oi said recess and a furtherprojection on said frame plate having an aperture for receiving a screwwhich threads into said magnetic frame,vsaid screw being accessible fromthe upper side oi said basefor enabling assembly and removal of saidcore member, energizing winding assenso and auxiliary frame plate whensaid device is mounted von a panel.l

3. A magnetically operable deviceoomprising a base o!insulating-material arranged to be mounted on a support with a bottomside next to the support and with an opposltely disposed top side. saidbase being provided with an opening, a magnetic `frame on the bottomside of said base and having a portion extending across said opening,said frame -belng provided with a leg extending -laterally from saidbottom side across one end of said base. a magnetic core member forminga second leg. an energizing winding on said core member, a magneticplate secured to one end of said core member having extensions pro-Jecting beyond the periphery of said winding. said plate and saidwinding iltting in said opening in said base', means cooperating withsaid extensions for detachably securing said plate to said frame withsaid plate in magnetic tiux conducting rdation with said portion ofsaidfi'ame.A

'4. A magnetically operable device comprising a base of insulatingmaterial provided with opmately disposed bottom and top sides, saidbcc'- I tom s'ide' being proviciedviritlia` groove and .said base beingProvided with -an'jopening communicatlnswithuid smovepa, A: ing a nrstleg nttingin'saidigroove and secured to said base; and encourt-legextending across one end of said top side, a magnetis'able core member,a magnetizable plate secured to one end of said. core member, anenergixing windingA mounted on said core member, extensions on saidplate projecting beyond the peripheryfoi said windt!!!` laid plateand'said winding iitting into said opening in said base into magneticnur conducting relation with said nrst leg, means cooperating with saidextensions and accessible from said top side of said base for detachably securing said plate to said nrst leg, whereby said coremen'ibenplate and winding are secured to said nrst leg and removable asa unit from said front aide oi' said base.

5. A magnetically operable device comprising a base of insulatingmaterial provided with oppositely disposed bottom and top sides, saidbottom side being provided with a groove and said base being providedwith an opening between said sides communicating with said groove, an L-shaped magnetizable trame having a iirst leg iitting' in said groove andsecured to said base, the second leg o! said frame extending across oneend of lsaid base to a point above said top side. amagnetizable coremember. a magnetizable plate secured to one end loi said core member, anenergizing winding mounted on said core member -against said plate,extensions on said plate proand winding are secured to said iirst legand removable as a unit from said front side of said base, and anarmature pivotally mounted on the end of said second ieg movable to anattracted position into engagement with the other end oi said coremember.

ALLEN G. STIMSON.

' frame hav-

